Triaryl phosphate mixtures



United States Patent This invention relates to novel mixtures of aryl triesters of orthophosphoric acid and to compositions containing them.

The art, as reviewed for exampleby Popkin in US.

Patent 3,034,877, is Well aware of the problems associated with the use of organolead compounds as antiknock agents in gasoline. In combating these problems, the art has generally resorted to the joint use of one or more halohydrocarbons, particularly ethylene dibromide and ethylene dichloride as first proposed by Midgely in US.

Patent 1,668,022 and further amplified by Bartholomew.

in US. Patent 2,398,281, which function to scavenge lead through the formation of divalent lead halides. Thus, lead, which otherwise would remain deposited in the combustion zone as oxidized lead, such as the oxide, oxyhalide and sulfate, may be exhausted from the engine in the form of relatively volatile dihalides. However, the halogen compounds are incompletely effective and the engine gradually accumulates deposits which contribute to such undesirable conditions as increase in the octane requirement of the engine, spark plug fouling by decreasing the electrical resistance of plug insulation, and untimely ignitions by inducing the fupl-air charge to fire before normal spark ignition can take place. The problem of preignition (also referred to as surface ignition) is particularly serious in high compression spark ignition engines. Erratic ignitions lead to rough engine operation, reduced power output, increased wear and erosion of engine parts.

The art has also long been aware that compounds of phosphorus are sometimes beneficial to inhibit spark plug misfiring, to suppress deposit-induced preignitions and to assist the normally employed halohydrocarbon additives in removing combustion chamber deposits. Popkin, in US. Patent 3,034,877, proposes to use monoalkyl diphenyl phosphates to solve some of these problems.

Fry et al., in US. Patent 2,375,218, disclose treating spark plug porcelains with a phosphorus compound, then heating to a high temperature to promote the desired reaction of the phosphorus compound with the deposits in or on the spark plug enamel. When the phosphorus compound is to be carried in a leaded gasoline, trimethyl phosphate is recommended since other phosphorus compounds are said to depreciate the antiknock value of the tetraethyl lead.

Livingston, in an article Antiknock Antagonists, Indusrial and Engineering Chemistry, 43, pp. 663670 (1951), reports that tetraethyl lead is extremely sensitive to the antagonism of phosphorus and its compounds.

In view thereof, British Patent 683,405 proposes the use of completely esterified organic esters of phosphorus (or arsenic) containing at least one carbocyclic radical. Tricresyl phosphate, triphenyl phosphate, Z-naphthyl diphenyl phosphate and trinaphthyl phosphate, among 0thers, are disclosed to be effective, individually, to offset the tendency of the octane requirement of the engine to increase with use, reduce exhaust valve corrosion, and counteract spark plug fouling, without adversely affecting fuel antiknock quality.

Yust and Barne, in US. Patent 2,889,212, which is apparently based on British Patent 683,405, disclose that the joint use of a halohydrocarbon scavenger and an alkaryl phosphate (or phosphite), e.g., tricresyl phosphate, substantially eliminates spark plug fouling without deleteriously affecting the antiknock characteristics of the fuel.

It appears that the alkaryl phosphate-halohydrocarbon scavenger compositions are especially designed for use in aviation fuels because of the relatively more frequent occurrences of spark plug fouling and the severity of the problem in aviation engines. In other words, the alkaryl phosphate-based compositions are selected primarily for their effectiveness as spark plug antifoulants on the basis of tests conducted with aviation grade gasolines. It appears that the presence of at least one alkaryl radical in the phosphorus compound is essential for good spark plug antifouling activity, as triphenyl phosphate is shown to be much less effective than tricresyl phosphate.

Aviation grade gasolines, as a rule, are especially olefinfree and contain not more than about 5'volurne percent of aromatic hydrocarbons. In recent years, motor fuels have been developed which contain substantial amounts of aromatics, first proposed by Wagner et al. in Improved Motor Fuels Through Selective Blending, paper presented before 22nd Meeting of the American Petroleum Institute, Nov. 7, 1941. The aromatic components constitute heavyends, i.e., high-boiling fractions of such gasolines, and these high aromatic content heavy-ends have been found more prone to produce deposits which cause surface ignition than other gasoline hydrocarbon types. Since, in multicylinder engines, fractionation of the fuel occurs during certain phases of engine operation, with light-end and heavy-end components being unevenly distributed to the various cylinders, the surface ignition problem tends to be further aggravated in cylinders getting a greater than normal share of aromatic components.

Thus, it is particularly desirable to be able to provide an effective means of controlling surface ignitions in modern high compression ratio spark ignition engines operating on high aromatic content motor gasolines.

While the art recognizes that one or more of such diverse problems as spark plug fouling, surface ignition, octane requirement increase, and exhaust valve corrosion may be attributed largely to the accumulation of combustion chamber deposits and may in part be alleviated through use of fuel additives, it has become keenly aware that more often an additive effective in one regard is disappointing in another. Thus, Gilbert, in Us. Patent 2,897,071, points out that the alleviation of spark plug failure is generally attained at the expense of both exhaust valve life and destructiveness of the organolead antiknock agent, and further states: Regarding many of the problems frequently associated with high octane quality fuel, an anomalous situation obtains. On one hand an effective adjuvant for organolead compounds should possess stability against deterioration in common environments, compatibility with the chemical entities with which it comes in contact, and volatility so as to possess the characteristic frequently referred to as engine inductibility. On the other hand, the mere selection of a phosphorus compound to acquire the optimum characteristics enumerated above does not necessarily assure the effectiveness of the compound in combating such phenomena as spark plug fouling, wild ping and the like. It is entirely probable that some empirical relationship between physical properties and effectiveness in the obviation of such problems exists, but as yet the state of the art does not contain a satisfactory relationship of this type.

It is an object of this invention to provide improved combustion chamber deposit scavenging compositions for use in leaded motor fuels, particularly those high in aromatic hydrocarbons. Another object is to provide novel triaryl phosphate compositions which are particularly effective, in conjunction with halohydrocarbon scavengers in leaded high octane number high aromatic content motor gasolines, to suppress surface ignition and combat spark plug fouling, and which tend to minimize the octane number requirement of the engine and reduce exhaust valve corrosion, substantially without adverse effect on the antiknock quality of the gasoline. Still another object is to provide such compositions which provide the further benefit of imparting significant anti-stall properties to motor gasolines at the same concentrations that are useful for attaining the above objects concerning combustion chamber performance. A further object is to provide new motor fuels comprised essentially of high octane number high aromatic content base gasolines, organolead antiknock agents, halohydrocarbon scavengers for lead, and novel triaryl phosphate compositions, to provide improved combustion chamber performance. A still further object is to provide such new motor gasoline compositions which show improved performance during the induction phase of engine operation as well as during the combustion phase. Other objects are to provide new compositions of matter and to advance the art. Still other objects will appear hereinafter.

The above and other objects are achieved according to this invention by employing, in aromatic mot-or fuels, organolead antiknock agents and halohydrocarbon lead scavengers in combination with novel triaryl phosphate compositions consisting essentially of (a) about 20 to about 50 mole percent of triphenyl phosphate,

(b) about 35 to about 60 mole percent of a two-ring-aryl diphenyl phosphate,

(c) about 10 to about 30 mole percent of a di(two-ringaryl) phenyl phosphate, and

(d) to about 6 mole percent of a tri(two-ring-aryl) phosphate,

(e) the mixed phosphates of (b) and (c) constituting a total of about 50 to about 80 mole percent of said mixture, and

(f) phenyl groups constituting about 60 to about 80 mole percent of all aryl groups in said phosphates.

Said novel triaryl phosphate compositions and antiknock compositions consisting essentially of organolead antiknock agents, with or without halohydrocarbon scavengers for lead, and said triaryl phosphate compositions also constitute important new compositions of this invention.

In the term two-ring-aryl as employed herein, aryl is used in the strict sense to mean an unsubstituted aromatic hydrocarbon radical, i.e., one which does not contain any alkyl or other substituent on the hydrocarbon rings. Thus, the two-ring-aryl radicals consist of naphthyl and biphenylyl radicals. Also, phosphate means ester of orthophosphoric acid.

The phenyl two-ring-aryl phosphate compositions of this invention are characterized by their many beneficial properties bearing on utility. They are liquid at normal room temperatures (about 25 C.), miscible with the halohydrocarbon scavenger and organolead anti-knock components, and readily soluble in liquid hydrocarbons of the gasoline boiling range. Substantially insoluble in water, they are not extracted from the mot-or fuel compositions, e.g., when stored over refinery water bottoms. They have not been found to be in any way harmful to the organolead antiknock blends or to the leaded motor fuel compositions. They are cleanly inductible with gasoline and impart significant antistalling properties thereto under conditions normally conducive to carburetor icing. As combustion chamber deposit modifiers, they are particularly effective to combat spark plug fouling and abnormal surface ignition phenomena. At the same time, they tend to reduce the weight of combustion chamber deposits, lower engine octane requirement, and decrease exhaust valve corrosion.

Essentially, the triaryl phosphate compositions of this invention are mixtures of (a) about 20' to about 50 mole percent of triphenyl phosphate, (b) about 35 to about 60' mole percent of a two-ring-aryl diphenyl phosphate, and

(0) about 10 to about 30 mole percent of a di(two-ringaryl) phenyl phosphate, wherein the mixed phosphates, (b) and (c) constitute a total of about 50 to about 80 mole percent of the mixture and the total of the phenyl groups in the mixture constitute about to about 80 mole percent of all aryl groups present in the mixture of phosphates. Normally, also, the two-ring-aryl diphenyl phosphate will be present in larger proportions than the di(two-ring-aryl) phenyl phosphate. The rather non-volatile tri(two-ring-aryl) phosphates, i.e., the trinaphthyl phosphates and the tribiphenylyl phosphates, are not essential components of the tri-aryl phosphate compositions of this invention and, most preferably, should be absent. However, it is not always economically practical to completely eliminate them from the compositions, and they may be tolerated in the compositions in proportions of up to about 6- mole percent, preferably not more than about 4 mole percent.

Preferably, the triaryl phosphate composition will consist essentially of (a) about 25 to about 45 mole percent triphenyl phosphate, (b) about 40 to about 55 mole percent two-ring-aryl diphenyl phosphate, (c) about 15 to about 25 mole percent di(two-ring-aryl) phenyl phosphate, and (d) 0 to about 4 mole percent tri(two-ringaryl) phosphate, the mixed phosphates of (b) and (c) constituting a total of about 55 to about 75 mole percent of said mixture and the phenyl groups constituting about to about mole percent of all aryl groups in said phosphates. A particularly preferred composition and distribution per mole is about 28 to about 32% triphenyl phosphate, about 44 to about 48% naphthyl diphenyl phosphate, about 20 to about 24% dinaphthyl phenyl phosphate, and 0 to about 4% trinaphthyl phosphate. Another particularly preferred composition and distribution per mole is about 29 to about 33% triphenyl phosphate, about 51 to about 55% biphenylyl diphenyl phosphate, about 12 to about 16% di-bipheny-lyl phenyl phosphate, and 0 to about 4% tri-biphenylyl phosphate. Mixtures of these compositions may be used. The napthyl radicals in the compositions may be l-naphthyl or Z-naphthyl or both, but preferably will be 2-naphthyl. The biphenylyl radicals may be one or more of 2-biphenylyl, 3-biphenylyl or 4-biphenylyl, but preferably will be 2-biphenylyl radicals.

The triaryl phosphate compositions of this invention are conveniently characterized in terms of the ratio of the phenyl radicals to the total aryl radicals, including phenyl radicals (which ratio multiplied by l00=mole percent phenyl). This ratio or phenyl radical content is directly related to the average molecular weight and the phosphorus content of the composition. Thus, the phosphate compositions of this invention which correspond to phen yl naphthyl triesters containing to 60 mole percent phenyl radicals have average molecular weights ranging from about 355 (8.7% wt. P) to about 385 (8.1% wt. P). Similarly, those corresponding to 80 to 60 mole percent phenyl radicals and 20' to 40 mole percent biphenylyl radicals as said triesters have average molecular weights ranging from about 372 (8.3% wt. P) to about 417 (7.4% wt. P). All these compositions are also characterized by their wide boiling range, at least about mole percent boiling over the range of about 225 C. to 350 C. at 5 mm. of Hg pressure.

The multi-component nature of these phosphate compositions is an important feature of the invention. Such compositions are surprisingly fluid compared to the individual components and show good fuel-induction characteristics. Their wide over-all boiling range, together with their good inductibility, may explain to some extent their over-all superior performance in the various critical zones of the combustion chamber, i.e., the exhaust valve region, the walls of the chamber and the spark plug area. Surprisingly, the multicomponent phosphate compositions of this invention are more effective than such commercially employed prior art alkaryl phosphate additives as tricresyl phosphate and cresyl diphenyl phosphate in controlling surface ignition, and are at least as effective as spark plug antifoulants despite their lower volatility per mole and total lack of alkaryl groups.

The triaryl phosphate compositions of this invention may be prepared by combining the individual components or mixtures thereof, in the designated proportions, said phosphates being obtainable in substantially pure condition by known methods of preparation and purification. Conveniently, the compositions are prepared directly starting with mixtures of phenyl and naphthy-l or biphenylyl radical sources which are converted to mixed phosphate esters in accordance with known techniques and procedures. For example, mixtures of phenol with beta-naphthol and/or with ortho-phenylphenol are reacted with phosphorus oxychloride in the presence of a catalyst such as AlCl or MgCl to produce mixed triesters of orthophosphoric acid. Norm-ally, mixtures, consisting of from 1.5 to 4 moles of the phenol, preferably 2 to 3 moles, for each mole of the naphthol or phenylphenol, are reacted with an equimolar proportion of phosphorus oxychloride and the catalyst in an amount of from 0.25-1% by weight of the charge at elevated temperaturesfinitially at 80 C.-110 C. and finally at 170 C.190 C.) until the evolution of the hydrogen chloride by-product is complete. The composition of the resulting product mixture is readily determined by known methods of analysis. Phenol: napthol or phenylphenol mole ratios of 1.5-4:1 normally produce mixtures consisting broadly per mole of 20-50% triphenyl phosphate, 35-50% two-ring-aryl diphenyl phosphate, -30% di(two-ring-aryl) phenyl phosphate, and from essentially nil (less than 1.0%) to 6% tri(two-ringaryl) phosphate. Preferred ratios of 2-321 yield mixtures composed of 25-45% triphenyl phosphate, 40-50% tworing-aryl diphenyl phosphate, 12 to 25% di(two-ring-aryl) phenyl phosphate, and up to 3% tri(two-ring-aryl) phosphate.

Normally, the product mixtures of the above process are washed acid-free with dilute alkali and water, and may be used in such form directly in accordance with this invention. If desired, the product may be distilled either for purposes of further purification, or to obtain one or more of' the individual components in the substantially pure state, or to alter the composition, e.g. by removing part of the triphenyl phosphate fraction or by distilling away the triphenyl and the unsymmetrical two-ring-aryl phenyl phosphates from the higher boiling tri(two-ring-' aryl) phosphate component.

The triaryl phosphate compositions of this invention will be used in conjunction with an organolead anti-knock agent in amounts providing about 0.013 to about 0.4 atom of phosphorus per atom of lead of the organolead antiknock agent, preferably about 0.033 to about 0.27 atom of phosphorus per atom of lead. These amounts, based on the formation of Pb (PO correspond to about 0.02 to about 0.6 theory of phosphorus, preferably about 0.05 to about 0.4 theory.

The organolead antiknock agent may be any of those known to the art for such purpose, but usually will be a lower (C -C tetraalkyl lead, such as tetramethyl lead, tetraethyl lead, methyl triethyl lead, dimethyl diethyl lead, trimethyl ethyl lead, tetraisopropyl lead, and the like, and mixtures of any two or more of such organolead antiknock agents, employed in an antiknock quantity, i.e. in an amount providing 0.1 to 6 grams of lead for each gallon of the motor fuel, preferably about 2 to 4 grams Pb/gal. Preferably, the antiknock agent will be one or more tetraalkyl lead compounds in which the alkyl groups contain 1-2 carbon atoms.

Also, the triaryl phosphate compositions will ordinarily be employed in conjunction with one or more halohydrocarbon scavengers for said lead, but may be used Without such scavengers. Such halogen sounce is believed not critical, on the basis for example that the phosphates of this invention have been found to effect substantially the same percent reduction in the incidence of surface ignition Whether in the absence or in the presence of halohydrocarbon scavengers. Better overall performance'has been obtained however with halohydrocarbon scavengers prescut.

The halohydrocarbon scavenger may be any of those known to the art for use in conjunction with organolead antiknock agents, particularly the halogenated aliphatic, cycloaliphatic and aromatic hydrocarbons wherein the halogens are of atomic numbers 17-35 and which contain 2 to 3 bromo and/ or chloro substituents and from 2 to 8 carbon atoms and normally boil below about 250 C. Usually preferred for this use however are the ethylene 'dihalides-the dibromide, the dichloride, and the chloro- .preferably about 2 to about 3 atoms (about 1 to about 1.5

theories) of halogen (Cl and/ or Br) per atom of lead of the organolead antiknock, and not more than 2 atoms of bromine for each atom of lead. Preferably, for motor fuel use, the quantity of bromine will not exceed about 1 atom of Br per atom of Pb, in other words, not exceed about 0.5 theory, the rest being chlorine.

The triaryl phosphate composition, halohydrocarbon scavenger, and organolead antiknock component may be premixed in any order and in any combination with one another to form antiknock blends for addition to the base fuel. Such blends may also contain other additives normally employed in their formulation, such as identifying dyes, neutral solvent oils (kerosene, toluene, xylene), and gasoline antioxidants. Of course, each additive may be added separately to the fuel or the phosphate composition itself may be added to preexisting leaded motor gasolines to produce the novel improved fuels of this invention.

The mixture of hydrocarbons which constitute the principal component of the fuel compositions of this invention may be a commercial gasoline containing the aromatic hydrocarbons in the defined amounts or it may be a blend of hydrocarbons of the character of those present in such gasolines. Thus, for example, it may be a catalytic-cracked stock, a catalytic-reformed stock, or blends of one or more of these cracked and reformed stocks, or blends of one or more of the above stocks with saturated stocks such as the synthetic alkylates and straight run stocks. Typical aromatic hydrocarbons, which are essential components of the motor fuels of this invention and which are of the character of those aromatic hydrocarbons which are produced in catalytic cracking and catalytic reforming operations, are the monoand poly-lower alkyl benzenes such as toluene, ethylbenzene, the xylenes, and the like. Typical catalytic-cracked refining stocks contain from about 6 to about 25 volume percent aromatic hydrocarbons, about 29-44 volume percent olefins, the rest saturated hydrocarbons. Catalytic-reformed stocks run higher in aromatics, usually about 40-70 volume percent, and are lower in olefins. Synthetic alkylates are essentially saturated hydrocarbons, high in isoparaflins. Stocks such as these are blended in various proportions for the production of commercial fuels for spark ignition engines. These fuels normally boil within the range of about F. to about 440 F. Blended fuels for commercial use, such as those for automotive use, contain on the average up to about 55 volume percent aromatic hydrocarbons, up to about 30 volume per-cent olefinic hydrocarbons, the rest saturated hydrocarbons.

The motor fuel-s of the present invention contain at least 15 volume percent, more usually at least 20 volume I 7 by the ASTM Research Method, most preferably a knock rating of 85 or better. The fuels may also contain other additives normally associated wtih finished gasolines, such as antioxidants, metal deactivators, dyes, detergents, and antiicing agents.

In order to more clearly illustrate this invention, preferred compositions and modes of practicing it and the advantageous results to be obtained thereby, the following examples are given in which the parts and proportions are by weight except where specifically indicated otherwise.

Example 1 A. A mixture, consisting of 11.75 lbs. of beta-naphthol (0.0816 lb. mole), 15.35 lbs. of phenol (0.1632 lb. mole), 12.56 lbs. of phosphorus oxychloride (0.0820 mole) and 0.18 lb. of anhydrous magnesium chloride, is heated in a 10 gallon glass-lined kettle equipped with an agitator and a reflux condenser at temperatures of from 80 C. to 110 C. for 16 hours, during which time HCl is expelled from the reaction mass. The charge is heated to 170 C. to complete the reaction, cooled, Washed acid-free in turn with water, dilute aqueous caustic at pH 10, again with water, and dried by heating at 110 C. under reduced pressure to yield 29.35 lbs. of a fluid (at normal room temperatures) mixture of phenyl naphthyl phosphates having high solubility in hydrocarbon solvents and having the properties shown hereinafter in Table 1. The great bulk of the product (94.2% by weight) comprises triphenyl phosphate, naphthyl diphenyl phosphate, and dinaphthyl phenyl phosphate distilling at from about 160 C. to about 265 C. at 0.2 mm. of Hg pressure, with the rest (5.8% weight) being still higher boiling and comprising mainly trinaphthyl phosphate.

Analysis by distillation indicated the composition to be 29 mole percent triphenyl phosphate, 45 mole percent Z-naphthyl diphenyl phosphate, 23 mole percent bis(2- naphthyl)-phenyl phosphate, and 3 mole percent tris(2- naphthyl) phosphate, which corresponds to a phenyl con- This product, which has a phenyl content of 33% and is thus outside the scope of this invention, will be referred to hereinafter as PN 33.

Example 2 Mixed 4-biphenylyl phenyl phosphates were prepared by the procedure of Example 1 from 170 parts 4-hydroxybiphenyl (1 mole), 188 parts phenol (2 moles), 154 parts POCl (1 mole) and 3 parts anhydrous MgCl by heating the mixture for 4 hours between 80 C. and 110 C., and then 8 hours at 180 C. The reaction mass was washed and dried as in Example 1 to yield a fluid (at normal room temperatures), motor gasoline-soluble product having other properties as given in Table 1 and having an overall composition of about 30 mole percent triphenyl phosphate, 51 mole percent 4-biphenylyl diphenyl phosphate, 18 mole percent bis(4-biphenylyl) phenyl phosphate and 1 mole percent tris(4-biphenylyl) phenyl phosphate. The product is referred to hereinafter as P4-B 70.

Example 3 Mixed Z-biphenylyl phenyl phosphates were prepared by the procedure of Example 2 except that Z-hydroxybiphenyl (1 mole) was used in place of the 4-hydroxy isomer. Washing and drying the reaction mass as in Example 1 yielded a fluid (at normal room temperatures), motor gasoline-soluble product having a phosphorus content of 7.8% by weight, in substantial agreement with the expected value. 96.2 percent of the product mixture distilled over the range 187 C. to 267 C. at 0.7 mm. of Hg pressure (or at 228 C. to 330 C. at 5 mm. of Hg pressure) to yield a distilled liquid mixture composed of 31 mole percent triphenyl phosphate, 55 mole percent 2-biphenylyl diphenyl phosphate, and 14 mole percent bis(Z-biphenylyl) phenyl phosphate, which corresponds to a phenyl content of 72%. This product mixture will be referred to hereinafter as P2-B 72.

TABLE 1.-SUMMARY OF PHYSICAL PROPERTIES. OF TRIARYL PHOSPHATES [Individual components and mixtures of Examples 1-3] Viscosity, Centistokes I Pour Point, at- Phosphate Physical State 1 Boiling Range 2 F.

(C6H5O)3PO Solid, M.I. 50 0. 245-250 0.]5 mm. (CGH50)2(2C10I'I70)PO Liquid 285290 C./5 mm- 67 (C H O) (2-C1 H O)PO dn 330-340 C./5 mm. 399 (2-C10H70)3P0 Solid, M P 110 C TN 67 of Example 1- Liquid 225-340 0.]5 mm 52 (0H5O) PO Solid, M P 50 C 3 245-250 C./5 mm. (COH50)2(2CQH5CBH40)PO Liquid 250285 C./5 mm. 20 6. 9 9o (CsHsO)(2-C5I'I5C H40)2PO d0 273-275 O./0.5 1 (2-C5H5COH40)3PO I P2-B 72 of Example 3 127 (Cs s0)a 0 (C0 5 )2( e 5CaHiO)PO (C H5O)(4-C0H5C0H4O) PO (4'C6II5CAH40)3PO P4B of Example 2 230-350 C./5 mm 97 4 Kosolapofi, Organic Phosphorus Compounds, Wiley, 1950, pp. 263-264.

5 Bass, U.S.P. 2,033,918.

' Britten, U.S.P. 1,858,659.

7 Britton and Bass, U.S.P. 2,117,291.

8 Solid. tent of 67 percent. This product mixture will be referred to hereinafter as PN 67.

B. For purposes of comparison, the above procedure is repeated except that the relative proportions of the naphthol and phenol are reversed, that is, there is employed 0.16 lb. mole of beta-naphthol and 0.08 lb. mole of phenol. The reaction product, a viscous liquid which solidifies to a low melting solid after some weeks standing at room temperatures, consists roughly of 4 mole percent triphenyl phosphate, 22 mole percent naphthyl diphenyl phosphate, 48 mole percent dinaphthyl phenyl phosphate, and 27 mole percent trinaphthyl phosphate.

The mixtures of Examples 1-3 are remarkably fluid (at normal room temperatures), especially in view of the fact that at least two of the four components in each mixture are normally solid and therefore also inherently viscous. Surprisingly, the liquid mixtures of this invention appear on the whole substantially no less pourable and no more viscous than the most fluid single member, yet they show an extended liquid range and an overall wide boiling range believed to be of advantage for the purposes of this invention as illustrated in the following examples.

Similarly, by the procedure of Example 1, there can 'be prepared a variety of multi-component phenyl two- 'ring-aryl triesters of orthophosphoric acid coming within the scope of this invention. Alternatively, individually prepared esters may be blended to produce representative compositionsrFor example, Table 2 shows multi-component phosphate-mixtures that can be obtained (A) by the method of 'Example'l, and (B) byblending the various phosphate esters in the proportions indicated. Compositions are in mole percent to the nearest Whole number. The phenyl index represents percent phenyl 'in the composition and, in vthecase of the compositions under A, also indicates the mole percent phenol in the starting phenolic mixture.

'10 v p The Deposit-Induced Surface Ignition Test was re peated on the same leaded gasoline composition of (A) in which there was .also incorporated a triaryl phosphate as identified in Table 3 below. It should be noted that the MIXTURES OF THIS INVENTION Accordlngto theProc ess of Example 1- Mole Percent Blended Compositions-Mole Percent Phosphate/Phenyl Index 6O 75 79 67 7D 75 (CaH50)3P0 22 42 49 45 (C6H50)2(C1OH70)PO 43 39 42 (C4H50)z(CaH5CaH40)PO. 43 .a 60 35 (0511 0) (C10H7O)2PO 29 12 23 (CaHaO) (osHsCaHlohPo 14 20 20 (C10H70)3PO 6 5 (CaH5CsH4O)aPO 1 Example 4 to the phenyl naphthyl phosphate composition not of this The eflectiveness of the phosphates of this invention to combatsurface ignition is shown by-meansof the Deposit- Induced Surface Ignition Test hereinafter described, involving the useof a singlevcyl'inder CF-R engine operated under the followingconditions:

Engine speed, r.p.m. 1800 Compression ratio --1-9.0:1 Spark timing, BTC 20 .Commutator timing, .AT C 8 Intake air temp., 'F. 200 Jacket temp., F. 212 Oil temp., F. 160 -Manifold air press, inches :Hg a'bs 20 Fuel-air ratio 0.075

.To determine the incidence ofsurface ignition, the en gine is allowed 19.5 minutes under the above conditions, then during the next0.5 minute the manifold air pressure isincreased to 3 0;inches of Hg absolute (to'simulate an acceleration) .and the occurrence of preignition (before the normal spark ignition in each cycle) is detected electronically by means of ionization probes inserted in the cylinder head. This cyclic procedure is repeated for a total of 40 hours running time and the observedoccurrences of deposit-induced surface ignitions are expressed as counts/ hour.

A.A reference line for Deposit-Induced Surface Ignition was established at 63 counts per hour by operating in the above test on a leaded aromatic type gasoline having an octane rating of 106.8 by the Research Method and 99.3 by the Motor Method and which was prepared by adding tetraethyl lead (TEL), ethylene dibromide and ethylene dichloride, in amounts providing 3 ml./gal. of the t-etraethyl lead, 0.5 theory of bromine and 1.0 theory of chlorine, to a motor gasoline base fuel composed of catalytic-reformed stocks providing 46 volume percent aromatic hydrocarbons, 1 volume percent-olefins and 53 volume percentsaturated hydrocarbons and having an octane rating .of 98.9 by .the Research Method and 89.9 by the Motor Method. With the same fuel composition prepared without :the halohydrocarbon scavenger components, the incidence of surface ignition was 130 counts per hour.

invention, PN 33 of Example 13.

TABLE 3.-REDUCING SURFACE IGNITION WITH TRIARYL PHOSPHATES Percent Reduction Concenin Surface Ignition Triaryl Phosphate tration, Theory P TEL TEL PN 67 of Example 1A 0.05 85 Pl-B 70-of Example 2. 0.05 'lricresyl phosphate. 0. 05 35 PN 67 of Example 1A. 0.1 57 "P2-B 72" of Example 3... 0.1 50 52 Cresyl diphenyl phosphate .0. 1 24 28 PN 67 ofExample 1A 0. 2 79 PN 33 of Example 1B 0. 2 69 Tricresyl phosphate 0. 2 62 Halohydrocarbon scavengers present in the proportions as described above in A.

2 No halohydrocarbon scavenger present.

vIt will be noted that the above demonstrated superiority ofthe phosphate compositions of this invention to control surface ignition is based on the use in an aromatic type gasoline. In contrast, PN 67" of Example 1A is less effective in this regard than tricresyl phosphate when employed in a non-aromatic gasoline. For example, 4 ml./ gal. of .tetraethyl lead, 1 theory of bromine as ethylene dibromide and either 0.0 or 0.2 theory of phosphorus as triaryl phosphate was blended into a base fuel which consisted of 5.5 volume percent aromatics, 20 volume percent olefinics and 92.5 volume percent saturates (thereby raising the Research Method octane rating from 93 to 1.06 and the Motor Method rating from to 103). According to the Deposit-Induced Ignition Test, the phenyl naphthyl phosphate composition PN 67 caused a 27% reduction, the tricresyl phosphate a 43% reduction, in the surface ignition rate.

The phenyl .two-ring-aryl phosphates of this invention are also superior to commercial prior art triaryl phosphate additives when employed in aromatic type motor gasoline in high compression multicylinder automotive engines, as shown in the following example.

Example 5 Tetraethyl lead, ethylene dichloride and ethylene dibromide, with and withouta triaryl phosphate as described .below, were blended into the gasoline base stock described in Example 4A in amounts providing 4.28 grams/gal. of lead, 1.0 theory of chlorine, 0.5 theory of bromine and 0.0, 0.3 or 0.7 theory of phosphorus as identified below. The resulting fuels (having Research Method octane ratings of about 107.8 and Motor Method ratings of about 100.4) were employed in the operation of a 12.5 :1 compression ratio GM Research eight cylinder engine under medium-duty, cyclic conditions involving 3.3 minutes at 1850 r.p.m. and 25 B.H.P. deceleration under load to idle, 1 minute idle at 700 r.p.m., and acceleration under load, with one of twelve accelerations per hour at full-throttle and eleven of twelve per hour part-throttle. The incidence of surface ignition occurring during the period of acceleration at full-throttle was sensed by means of ionization probes in each cylinder head. The results are tabulated in Table 4 as counts/hour (observed as a steady value over a period of at least 100 consecutive hours of operation) and percent lowering of preignition effected by the additives.

posed plugs is rated individually in the No. 1 cylinder of the engine. But first, new plugs are installed in all cylinders and the engine load adjusted to give 3-200 r.p.m. at the end of a 20 second wide-open-throttle (WOT) acceleration from 1500 r.p.m., HF. load. The WOT acceleration is repeated several times to bring the engine to equilibrium. Then the test plug is installed and the engine is given (a) a warmup of 2 minutes alternating between 800 r.p.m. no load (idle) and 1500 r.p.m. brake horsepower (road load) then (b) one full-throttle acceleration during which spark plug misfire is detected by means of an ion gap counter.

By means of this test, various triaryl phosphates were compared as to effectiveness as spark plug antifoulants in a typical leaded aromatic type motor gasoline--the fuel more particularly described in Example 4A. The results are expressed in Table 5 in terms of the number of hours of plug exposure to 10% misfiring. Such time, which is not a multiple of 20 hours, is obtained by interpolation.

TABLE 4. REDUCING SURFACE IGNITION IN MULTICYLINDER ENGINE TEST WITH TRIARYL PHOSPHA'IES It will be noted that a much higher dosage of the commercial cresyl diphenyl phosphate (0.7 theory P) is needed to match the effectiveness of the phenyl naphthyl phosphate composition PN 67 of this invention at the 0.3 theory P level.

At the end of each run, the intake system was found clean and free of abnormal deposits. In general, combustion chamber deposits tended to be lower with phosphorus present in the fuel, and both visual inspection and compression pressure tests showed no adverse effect of phosphorus on the valves. Also, it was observed (in the single cylinder as well as the multicylinder engine tests) that, while none of the phosphates had a significantly adverse effect on engine octane requirement, in general the lower the surface ignition count the lower the engine octane requirement.

Example 6 The phosphate compositions of this invention are also highly effective to combat spark plug misfiring, as illustrated in the Spark Plug Misfiring Test described below, involving the operation of a standard production V-8 Oldsmobile engine according to a spark plug deposit accumulation cycle and 2. Spark Plug Rating Cycle.

In the deposit accumulation cycle, new AC-44 plugs are installed in a clean engine and the engine run for a total of 20 or more hours under the following conditions:

TABLE '5.-EFFECTIVENESS OF TRIARYL PHOSPHATES AS SPARK PLUG ANTIFOULA'NTS [Fuel: Aromatic motor gasoline containing 3 ml. TEL (mm.)l gal.+0.l theory P as triaryl phosphate] *Plug performance Triaryl phosphate: hrs. to 10% misfire None 46 Cresyl diphenyl phosphate 73 Z-biphenylyl diphenyl phosphate 84 PZ-B 72 of Example 3 99 TN 67 of Example 1 100 Example 7 To a full boiling gasoline (initial point 100 F., 10% point 132 F., point 222 F., 90% point 323 F. and end point 398 F.) a blend consisting essentially of reformate, 30% alkylate and 15% isopcntane, and

Time Secs. Speed Load Oll Temp., Coolant Coolant F. Temp. in Temp. out

30 500 0 160 145 160 30 1, 500 Road (15 HP)... i3 i3 i3 composed of 28% aromatics, 1% olefins and 71% saturates all by volume, was added 3 ml. tetraethyl lead per gallon, 1.0 theory of ethylene dichloride, 0.5 theory of ethylene dibromide, and 0.4 or 1.0 theory P (th. P) as identified below in Table 6. The antiknock properties, Research octane number (R.O:N.) of the fuel compositions were determined by the ASTM Research Method with the results shown in Table 6.

TABLE 6.EFFECT OF TRIARYL PHOSPHATE ON LEADED RESEARCH OCTANE NUMBER The tabulated-data showthat the triaryl phosphates of this invention are substantially non-antagonistic to tetraalkyl lead'antiknocks.

Phosphate compositions of this invention, exemplified by PN 67 of Example 1A, provide still another benefit of inhibiting engine stalling due to carburetor icinga common occurrence in the operation of an internal combustion engine, during warm-up andlidling, under cool, humid atmospheric conditions. Stalling is attributed to the formation of ice particles in the carburetor, especially on the throttle plate and surrounding walls, caused by a lowering in the temperature of the metal parts of the carburetor as the fuel vaporizes.

Example 8 Antistalling effectiveness of the additives of this invention is illustrated by means of the Carburetor Icing Test described below which is designed to evaluate carburetor icing tendencies of motor gasolines and the effectiveness of additives under severe icing conditions. The engine is a standard 6-cylinder Chevrolet engine, having a horsepower rating of 86 at 3400 r.p.m. and a displacement of 216.5 cu. in., operated under the following conditions:

Intake air 38-40 F. Relative humidity Approx. 100%. Engine load 10 horsepower. Engine speed 1500 r.p.m. Idle speed 350400 r.p.m.

Fuel temp. to carburetorn 50-55 F.

Before starting each. run, the throttle plate is first cleaned and conditioned by soaking it in alcohol for 0.5

minute at a temperature of 40 F. Fuels are rated by '1.p.1n. under a load necessary to cause stalling while idling. With commercial gasolines without antiicing pro tection, stalling generally occurs-within 0.5 to 1.25 "min- The results obtained with this gasoline are given in Table 7 and show that the phosphate compositions of this invention also provide significant antistall resistance to motor fuels normally tending to stall. due to carburetor icing.

.50 the number ofminutes of open-throttle operation at 1500 TABLE 7.EFFECT OF TRIARYL PHOSPHATES ON CAR- BURETOR ICING OF MOTOR GASOLINE Concentration Minutes of Triaryl Phosphate Stall-Free Operation 'G./gal. Theory P PN 67" of Example 1 0.38 0.1 1. 5

N hth ldi h 1 h h t 2- a p eny osp a 0.-

p y p 1.15 0.3 0.5 None 0 0 0.5

Itwill be noted here too that PN 67 and the Z-naphthyl diphenyl phosphate have substantially identical empirical formulas (phenyl content=67%) and do not appear to differ markedly in fluidity (Table 1). Still they are not equivalent in this test.

,It will be noted that PN 67 is effective in this regard during the induction phase of the engine operation in.

precisely those concentrations which are highly effective to improve the operation of the engine during the combustion cycle. Moreover, the. phosphate compositions'of this invention are compatible, in respect to inhibiting carburetor icing, with commercial antistall agents and may be used advantageously therewith, a particularly notable class consisting essentially of gasoline-soluble amine salts of alkyl acid phosphates. Such phosphoruscontaining antistall additives are not normally employed in quantities sufiicient also to exert significant beneficial effects on combustion chamber phenomena.

One class of such amine salts which may be used is described by Cantrell 'et al. in US. Patent 2,863,904. Another highly preferred class comprises normally liquid neutral amine salts of branched chain primary alkyl acid esters of orthophosphoric acid in which each esterfying alkyl group contains 13 to 16 carbon atoms and the amine is an aliphatic hydrocarbon monamine of 6 to 24 carbon atoms in which each aliphatic hydrocarbon radical is attached to the nitrogen through a saturated carbon atom. Preferred are the amine salts of approximately equimolar mixtures of the monoand di-alkyl esters containing about 40 to about 60 mole percent of the monoalkyl esters and about 60 to about 40 mole percent of the dialkyl esters. It is particularly preferred that the alkyl groups in said esters be oxo-tridecyl groups, i.e. branched C alkyl groups corresponding to the alkyl portion of the branched tridecyl alcohol obtained by the oxo-process from tetrapropylene, carbon monoxide and hydrogen, and that the amine employed in forming the salt be a branched chain alkyl primary amine such as Z-ethylhexylamine or a C -CH tertiary alkyl primary amine.

The novel triaryl phosphate compositions of this invention can be formulated with such amine alkyl acid TABLE 8.MULTIPURPOSE ANTISTALL AND ANTI- PREIGNITION PHOSPHORUS COMPOSITIONS Percent Weight "Ingredient A B Alkylamine salt of alkyl acid phosphate 13. 7 8. 0 Methanol 33. 4 59. 1 Kerosene 2. 0 P2-B 72" of Example 3 53.9 30.9

Example 9 Tetraethyl lead antiknock blends A and B of Table 9 below, having improved deposit-modifier characteristics, were prepared by mixing 1.20 and 28.8 parts of PN 67 of Example 1A with 100 parts of a mixture of the other ingredients shown in Table 9 to form clear, homogeneous liquid blends.

TABLE 9.ANTIKNOCK BLENDS OF THIS INVENTION- 'Similar mixes can be prepared from the other phosphate mixtures of this invention, by substituting for example P4-B 70 of Example 2 and P2B 72 of Example 3.

In addition to those described in the foregoing examples, a wide variety of improved motor gasolines can be formulated in accordance with this invention. For example multi-component phosphate composition of phenyl index 60 described in Table 2 can be blended to a concentration of 0.39 gram/gal. (about 0.1 theory) with a motor gasoline characterized by its composition by volume of 24 percent of aromatics, 42 percent of olefins, and 34 percent of saturates, its content of 5.07 ml./ gal. of tetraethyl lead antiknock mix comprising 3 mL/ gal. of tetraethyl lead, 1.5 grams/ gal. of ethylene dichloride (1 theory), and 1.44 grams/ gal. of ethylene dibromide (0.5 theory), and the base fuels API gravity of 641 (accord-. ing to ASTM Test Procedure D-287), vapor pressure of 13.8 p.s.i. (according to ASTM Test Procedure D323) and (according to ASTM Test Procedure D-86) initial boiling point of 84 F., 10 percent point of 110 F., midboiling point of 195 F., 90 percent point of 306 -F., and final boiling point of 387 F. Similarly there can be prepared a motor fuel containing 3.18 grams Pb./ gal. as tetraethyl lead with conventional scavengers (1 theory ethylene dichloride and 0.5 theory ethylene dibromide) and 0.3 theory of phosphorus by blending the tetraethyl lead, the scavengers, and the Table 2 composition of phenyl index 79 into a gasoline base stock composed by volume of 44 percent of aromatics, 17 percent of olefins, and 39 percent of saturates, and having a gravity of 547 API, a vapor pressure of 9.6 p.s.i., an initial boiling point of 97 F., a 10 percent point of 129 F., a mid-boiling point of 234 F., a 90 percent point of 307 F., and final boiling point of 350 F.

Similarly, also, three finished fuels can be prepared from a base stock containing by volume 24 percent aromatics, 2 percent olefins, 74 percent saturates and having a gravity of 615 API, a vapor pressure of 9.5 p.s.i., initial boiling point of 88 F., a 10 percent point of 130 F., mid-boiling point of 222 F., a 90 percent point of- 318 F., and final boiling point of 384 F., (a) by blending one portion of this base fuel with 2 grams Pb/ gal. as tetramethyl lead, 0.025 theory of P as the composition of phenyl index -67 described in Table 2, 1.0 theory ethylene dichloride and 0.5 theory ethylene dibromide; (b) by blending a second portion with 0.2 theory of P as P2B 72 of Example 3 and 4.0 grams Pb/gal. in the form of a mixture of tetraalkyl leadsanalyzing approximately 6 mole percent tetramethyl lead, 25 mole percent trimethyl ethyl lead, 38 mole percent dimethyl diethyl lead, and 25 mole percent methyltriethyl lead, and 6 mole percent tetraethyl lead, together with 0.5' theory bromine as ethylene dibromide and 1.0 theory chlorine as ethylene dichloride;

16 and (c) by blending the third portion of the base stock with 0.1 theory of P as the composition having phenyl index 75 in Table 2 and 3.25 grams Pb/ gal. as an equimolar mixture of tetramethyl lead and tetraethyl lead and containing conventional scavenging agents as in the second portion.

Still another useful leaded and phosphated fuel composition of this invention can be obtained by adding PN 67 of Example 1A at a concentration of 2.31 grams/ gal. (0.6 theory) to a motor gasoline composed by volume 15 percent aromatics, 16 percent olefins, and 69 percent saturates and containing 3.0 grams Pb/gal. as tetraethyl lead together with 1.5 theories ethylene dichloride as scavenging agent.

It will be understood that the preceding examples have been given for illustrative purposes solely and that this invention is not limited to the specific embodiments described therein. On the other hand, it will be readily apparent to those skilled in the art that, subject to the limitations set forth in the general description, variations and modifications can be made in the materials, proportions and techniques employed without departing from the spirit or scope of this invention.

From the foregoing description, it will be apparent that this invention provides novel triaryl phosphate compositions, novel antiknock blends containing them, and novel motor fuels composed of aromatic base fuels containing organolead antiknock agents and the triaryl phosphate compositions. The triaryl phosphate compositions of this invention have a novel combination of advantageous properties, whereby, when they are used in such motor fuels, they serve a multiplicity of purposes to impart to the motor fuels a combination of highly beneficial properties not heretofore obtainable with a single additive or with related phosphate compositions. Accordingly, it will be apparent that this invention constitutes a valuable advance in and contribution to the art.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A triaryl phosphate composition consisting essentially of a mixture of (a) about 20 to about 50 mole percent of triphenyl phosphate,

(b) about 35 to about 60 mole percent of a two-ringaryl diphenyl phosphate,

(0) about 10 to about 30 mole percent of a di(two-ringaryl) phenyl phosphate, and

(d) 0 to about 6 mole percent of a tri(two-ring-aryl) phosphate,

(e) the mixed phosphates of (b) and (c) constituting a total of about 50 to about mole percent of said mixture, and

(f) the phenyl groups constituting about 60 to about 80 mole percent of all aryl groups in said phosphates.

2. A triaryl phosphate composition consisting essentially of a mixture of (a) about 25 to about 45 mole percent of triphenyl phosphate,

(b) about 40 to about 55 mole percent of a two-ringaryl diphenyl phosphate, and

(0) about 15 to about 25 mole percent of a di(tworing-aryl) phenyl phosphate,

(e) the mixed phosphates of (b) and (c) constituting a total of about 55 to about 75 mole percent of said mixture, and

(f) the phenyl groups constituting about 65 to about 75 mole percent of all aryl groups in said phosphates.

3. A triaryl phosphate composition consisting essentially of a mixture of V (a) about 20 to about 50 mole percent of 'tI'lP y phosphate,

1(b) about 35 to about 60 mole percent of a naphthyl diphenyl phosphate,

(c) about 10 to about 30 mole percent of a dinaphthyl phenyl phosphate, and

(d) to about 6 mole percent of a trinaphthyl phosphate,

(e) the mixed phosphates of (b) and (c) constituting a total of about 50 to about 80 mole percent of said mixture, and

(f) the phenyl groups constituting about 60 to about 80 mole percent of all aryl groups in said phosphates.

4. A triaryl phosphate composition consisting essentially of a mixture of (a) about 28 to about 32 mole percent of triphenyl phosphate,

(b) about 44 to about 48 mole percent of a n'aphthyl diphenyl phosphate,

(c) about 20 to about 24 mole percent of a dinaphthyl phenyl phosphate, and

(d)h0 to about 4 mole percent of a trinaphthyl phosp ate.

5. A triaryl phosphate composition consisting essentially of a mixture of (a) about 20 to about 50 mole percent of triphenyl phosphate,

(b) about 35 to about 60 mole percent of a biphenylyl diphenyl phosphate,

(c) about 10 to about 30 mole percent of a dibiphenylyl phenyl phosphate, and

(d) 0 to about 6 mole percent of a tri-biphenylyl phosphate,

(e) the mixed phosphates of (b) and (c) constituting a total of about 50 to about 80 mole percent of said mixture, and

(f) the phenyl groups constituting about 60 to about 80 mole percent of all aryl groups in said phosphates.

6. A triaryl phosphate composition consisting essentially of a mixture of (a) about 29 to about 33 mole phosphate,

(b) about 51 to about 55 mole percent of a biphenylyl diphenyl phosphate,

(c) about 12 to about 16 mole percent of a dibiphenylyl phenyl phosphate, and

(d)h0 to about 4 mole percent of a tri-biphenylyl phosp ate.

7. An antiknock blend consisting essentially of (A) an organolead antiknock agent,

(B) at least one halohydrocarbon scavenger for lead in an amount providing 1 to atoms of halogen of atomic numbers 17-35 for each atom of lead of said organolead antiknock agent, and

(C) a triaryl phosphate composition as defined in claim 1 in an amount providing about 0.013 to about 0.4 atom of phosphorus for each atom of lead of said organolead antiknock agent.

8. An antiknock blend consisting essentially of (A) a tetraalkyl lead antiknock agent, in which the alkyl groups contain 1-2 carbonatoms,

(B) at least one ethylene dihalide in which the halogens are of atomic numbers 17-35 in an amount to provide about 2 to about 3 atoms of halogen and not more than 2 atoms of bromine for each atom of lead of said tetraalkyl lead antiknock agent, and

(C) a triaryl phosphate composition as defined in claim 1 in an amount providing about 0.013 to about 0.4 atom of phosphorus for each atom of lead of said tetraalkyl lead antiknock agent.

9. An antiknock blend consisting essentially of (A) a tetraalkyl lead antiknock agent, in which the alkyl groups contain 1-2 carbon atoms,

(B) at least one ethylene dihalide in which the halogens are of atomic numbers 17-35 in an amount to provide about 2 to about 3 atoms of halogen and not more than 2 atoms of bromine for each atom of lead of said tetraalkyl lead antiknock agent, and

percent of triphenyl '(C) a triaryl phosphate composition as defined in claim 3 in an amount providing about 0.013 to about 0.4 atom of phosphorus for each atom of lead of said tetraalkyl lead antiknock agent.

10. An antiknock blend consisting essentially of (A) a tetraalkyl lead antiknock agent, in which the alkyl groups contain 1-2 carbon atoms,

(B) at least one ethylene dihalide in which the halogens are of atomic numbers 17-35 in an amount to provide about 2 to about 3 atoms of halogen and not more than 2 atoms of bromine for each atom of lead of said tetraalkyl lead antiknock agent, and

(C) a triaryl phosphate composition as defined in claim 4 in an amount providing about 0.013 to about 0.4 atom of phosphorus for each atom of lead of said tetraalkyl lead antiknock agent.

11. An antiknock blend consisting essentially of (A) a tetraalkyl lead antiknock agent, in which the alkyl groups contain 1-2 carbon atoms,

(B) at least one ethylene dihalide in which the halogens are of atomic numbers l7-35 in an amount to provide about 2 to about 3 atoms of halogen and not more than 2 atoms of bromine for each atom of lead of said tetraalkyl lead antiknock agent, and

(C) a triaryl phosphate composition as defined in claim 5 in an amount providing about 0.013 to about 0.4 atom of phosphorus for each atom of lead of said tetraalkyl lead antiknock agent.

12'. An antiknock blend consisting essentially of (A) a tetraalkyl lead antiknock agent, in which the alkyl groups contain 1-2 carbon atoms,

(B) at least one ethylene dihalide in which the halogens are of atomic numbers 17-35 in an amount to provide about 2 to about 3 atoms of halogen and not more than 2 atoms of bromine for each atom of lead of said tetraalkyl lead antiknock agent, and

(C) a triaryl phosphate composition as defined in claim 6 in an amount providing about 0.013 to about 0.4 atom of phosphorus for each atom of lead of said tetraalkyl lead antiknock agent.

13. A motor fuel consisting essentially of a mixture of liquid hydrocarbons boiling in the gasoline boiling range of which at least 15% by volume are aromatic hydrocarbons of the character of those occurring in catalytically cracked and reformed gasolines, said mixture of hydrocarbons having an octane rating of at least as measured by the ASTM Research Method, and which motor fuel contains (A) an organolead antiknock agent in an amount to provide 0.1 to about 6 grams of lead for each gallon of the motor fuel,

(B) at least one halohydrocarbon scavenger for lead in an amount providing 1 to 5 atoms of halogen of atomic numbers 17-35 for each atom of lead of said organolead antiknock agent, and

(C) a triaryl phosphate composition as defined in claim 1 in an amount providing about 0.013 to about 0.4 atom of phosphorus for each atom of lead of said organolead antiknock agent.

14. A motor fuel consisting essentially of a mixture of liquid hydrocarbons boiling in the gasoline boiling range of which at least 15% by volume are aromatic hydrocarbons of the character of those occurring in catalytically cracked and reformed gasolines, said mixture of hydrocarbons having an octane rating of at least 80 as measured by the ASTM Research Method, and which motor fuel contains (A) a tetraalkyl lead antiknock agent in which the alkyl groups contain 1 to 2 carbon atoms in an amount to provide 0.1 to about 6 grams of lead for each gallon of the motor fuel,

(B) at least one halohydrocarbon scavenger for lead in an amount providing 1 to 5 atoms of halogen of atomic numbers 17-35 for each atom of lead of said tetraalkyl lead antiknock agent, and

(C) a triaryl phosphate composition as defined in claim halogen of atomic numbers 17-35 for each atom of 1 in an amount providing about 0.013 to about 0.4 lead of said tetraalkyl lead antiknock agent, and t f phosphorus f h t f l d ofid (C) a triaryl phosphate composition as defined in claim tetraalkyl lead amiknock agent 1 in an amount providing about 0.013 to about 0.4

15. A motor fuel consisting essentially of a mixture of 5 atom Qf Phosphorusfor each atom of lead of said liquid hydrocarbons boiling in the gasoline boiling range tetraalkyl lead antiknock agentof which at least 15% by volume are aromatic hydrocarbons of the character of those occurring in catalytically cracked and reformed gasolines, said mixture of hydro- References Cited UNITED STATES PATENTS carbons having an octane rating of at least 85 as meas- 10 2,862,801 1 /1958 DeWitt 44--69 ured by the ASTM Research Method, and which motor ,99 9 9/1961 Heron 4469 f l contains 3,038,791 6/ 1962 Orlotf et a1 4469 (A) a tetraalkyl lead antiknock agent in which the 3052528 9/1962 Roddick et 44' 69 alkyl groups contain 1 to 2 carbon atoms in an 15 FOREIGN PATENTS amount to provide 0.1 to about 6 grams of lead for 683,405 11/1952 Great Britain.

each gallon of the motor fuel, (B) at least one halohydrocarbon scavenger for lead DANIEL WYMAN in an amount providing about 2 to about 3 atoms of W. I. SHINE, Assistant Examiner. 

1. A TRIARYL PHOSPHATE COMPOSITION CONSISTING ESSENTIALLY OF A MIXTURE OF (A) ABOUT 20 TO ABOUT 50 MOLE PERCENT OF TRIPHENY PHOSPHATE, (B) ABOUT 35 TO ABOUT 60 MOLE PERCENT OF A TWO-RINGARYL DIPHENYL PHOSPHATE. (C) ABOUT 10 TO ABOUT 30 MOLE PERCENT OF A DI(TWORING-ARYL) PHENYL PHOSPHATE, AND (D) 0 TO ABOUT 6 MOLE PERCENT OF A TRI(TWO-RING-ARYL) PHOSPHATE, (E) THE MIXED PHOSPHATES OF (B) AND (C) CONSTITUTING A TOTAL OF ABOUT 50 TO ABOUT 80 MOLE PERCENT OF SAID MIXTURE, AND (F) THE PHENYL GROUPS CONSTITUTING ABOUT 60 TO ABOUT 80 MOLE PERCENT OF ALL ARYL GROUPS IN SAID PHOSPHATES.
 13. A MOTOR FUEL CONSISTING ESSENTIALLY OF A MIXTURE OF LIQUID HYDROCARBONS BOILING IN THE GASOLINE BOILING RANGE OF WHICH AT LEAST 15% BY VOLUME ARE AROMATIC HYDROCARBONS OF THE CHARACTER OF THOSE OCCURRING IN CATALYTICALLY CRACKED AND REFORMED GASOLINES, SAID MIXTURE OF HYDROCARBONS HAVING AN OCTANE RATING OF AT LEAST 80 AS MEASURED BY THE ASTM RESEARCH METHOD, AND WHICH MOTOR FUEL CONTAINS (A) AN ORGANOLEAD ANTIKNOCK AGENT IN AN AMOUNT TO PROVIDE 0.1 TO ABOUT 6 GRAMS OF LEAD FOR EACH GALLON OF THE MOTOR FUEL. (B) AT LEAST ONE HALOHYDROCARBON SCAVENGER FOR LEAD IN AN AMOUNT PROVIDING 1 TO 5 ATOMS OF HALOGEN OF ATOMIC NUMBERS 17-35 FOR EACH ATOM OF LEAD OF SAID ORGANOLEAD ANTIKNOCK AGEN, AND (C) A TRIARYL PHOSPHATE COMPOSITION AS DEFINED IN CLAIM 1 IN AN AMOUNT PROVIDING ABOUT 0.013 TO ABOUT 0.4 ATOM OF PHOSPORUS FOR EACH ATOM OF LEAD OF SAID ORGANOLEAD ANTIKNOCK AGENT. 